Method for making filaments



Aug 3l, 1943; H. BUcHsBAUM z-:T A1. 2,328,125

METHOD FOR MAKING FILAMENTS Filed Feb. 17, 1940 2 Sheets-Sheet l Z @WLy-Avlg- 31, 1943- H. BUcHsBAUM ET AL 2,328,125

METHOD FOR MAKING FILAMENTS Filed Feb. 1'?, 1940 2 sheets-sheet 2 N V A3 Patented Aug. 31, 1943 METHOD FOR MAKING FILAMENTS Herbert Buchsbaumand Leonard Becker, Chicago, Ill., assignors to S. Buchsbaum & Company,Chicago, Ill., a corporation of Illinois Application February 11, 1940,serial No. 319,458

4 Claims.

This invention relates to a method and means for making artificialfibers and filaments and more particularly to an improved method andapparatus for making vinyl resin laments.

Avprincipal object of this invention is to .provide a simple,inexpensive and continuous process of making vinyl resin filamentssuitable for textile fibers.

A further object is to provide a process whereby fibers of vinyl resincomposition are formed, stretched, set and coned or reeled in one simplecontinuous operation.

Another object is to provide an improved apparatus for continuouslyforming, stretching, setting and winding textile filaments.

Other objects and advantages of the invention will become apparent asthe following description proceeds, reference being had to theaccompanying drawings in which- Fig. 1 is a diagrammatic plan Viewshowing the process and apparatus of this invention;

Fig. 2 is a section taken on the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary plan view of the leveling and winding mechanism;

Fig. 4 is a plan view taken along line 4 4 of Fig.2;

Fig. 5 is a vertical section taken' on the line 5-5 of Fig.4; and g Fig.6 is a section taken on the line 6-6 of Fig. 4.

In accordance with this invention an elastic vinyl resin composition isheated to a molten and non-elastic state, the molten non-elasticcomposition continuously drawn into a filament which is placed underelastic stretch, cooled while under such stretch, and then wound on areel or drum.

In the embodiment of the invention shown in thedrawings. the moltennon-elastic vinyl resin composition is continuously fed through an 'I'hemolten composition in the process of being drawn into a filament G fromthe supply cup 5 first forms a cone ll which diminishes in crosssectioninto the filament 6 of the size of a textile ber. The composition whenit iirst emerges from the supply cup is hot and in a non-elastic state.As the composition in the form of a lament travels from the supply cupthe atmosphere quickly cools it to an elastic condition and gives itstrength suflicient to withstand the constant pull from the windingmechanism.

The winding mechanism is run atv such a rate as to give a filament ofthe size of a textile fiber, and also at such speed in relation to thefeed mechanism as to stretch the lament. The stretched filament iscooled by passing the filament over a cold roller or pulley 1 or byother suitable means. Cooling of the stretched lament to below C. andpreferably to below 30 C. sets the fiber, gives improved tensilestrength and other characteristics of value for textile fibers.

In one embodiment of the invention the stretched filament instead ofbeing cooled by the atmosphere or by passing over a chilled roller isdrawn through water which may be regulated to any desired temperature,such as 0 C. or any other temperature at which the stretched fiber tendsto set. In this manner the advantageous effect of water on vinyl resinber is quickly and economically utilized. C.

In order to obtain further improvement the fiber made by the continuousdrawing, stretching and cooling process may be immersed in hot water,viz. water at 212 F., stretched to substantially its elastic limit, andimmersed while still stretched in cold water, viz. water at 32 F. Thisprocess may be repeated several times with advantageous results.

In carrying out the continuous process of this invention, it isdesirable to employ an elastic vinyl resin composition which isthermoplastic and relatlvely non-elastic at temperatures above normalroom temperature and below the decomposition temperature. Suchcompositions should be solid and non-tacky at normal roomtemperaturesand preferably Within a range of from 0 F. to l1 00?. F.Another important characteristic is thatthematerial in the form of afilament of .05 mm. in diameter should be capable of being creasedwithout appreciable cracking. The material should also have an ultimatetensile strength of at least 1000 lbs. per sq. inch and an elasticextensibility of at least of its length. Preferably, under a tensilestress of 1,000 lbs per sq. inch the material should stretch 100% of itslength within the elastic limit in a period of at least 10 seconds,

and on removal of the tensile stress, the material should also returnsubstantially to its original dimensions and require a period to returnfrom 100% to 50% of its original dimensions of from 5 to 2'0 seconds.Such a material has the characteristics which make it suitable forcontinuous direct drawing, stretching, cooling and winding.

Suitable compositions ordinarily consist essentially of a vinyl resinhaving an average macro molecular weight of at least 15,000, combinedwith a plasticizer which gives the required flexibility and elasticitywithout lowering the tensile strength below 1000 lbs per sq. inch orbelow the limits necessary for continuous drawing, stretching andwinding.

The class of vinyl resins particularly `useful in.

this invention are those such as are described in Patent 1,935,577 to E.W. Reid, andi these resins maybe made by the processes described by thatpatent or by other means such as the process described in Patent2,064,566 to E. W. Reid. 0f these conjoint polymers of vinyl halideswith vinyl esters of aliphatic acids, the 'preferred resins are thosewhich contain from 80 to 95% by weight of the halide in the polymer.Within this range those resins formed from vinyl chloride and vinylacetate which contain in the polymer about 85% to 90% by weight of thechloride are especially desirable. However, the invention is not limitedto the use of these particular vinyl resins but may be carried out withother types of vinyl resins such as the polyvinyl' chlorides, polyvinylacetals, mixtures of polyvinyl chlorides and polyvinyl acetates,provided the resin has the desired strong, flexible, threadformingphysical characteristics described above or may be modied by theaddition of plasticizers to obtain the described characteristics. In thecase of conjoint polymers of vinyl chloride and vinyl acetate having anaverage molecular weight oi at least 15,000, the resin desirably shouldbe modified with substantial proportions of plasticizer in order toobtain the characteristics necessary in order to make it suitable forcontinuously drawing, stretching and winding, and this in general isdesirable for all the vinyl resins which have tensile strength suitablefor textile fibers.

Suitable and preferred proportions of plasticizer will vary somewhatwith the type of vinyl resin and the type of plasticizer. It is highlyimportant that the amount and type of plasticizer should not be such asto give a tacky composition at normal room temperature, and preferablybetween ctemperatures of 0 F. to 100 F. At thel same time theplasticizer must be of such type and present in such amount that thetensile strength of the composition is suitable for continuous drawing,stretching and winding, and such that the filament can be readilyflexed.

We have found it desirable to use over 21% by weight of plasticizer onthe vinyl resin and prefl erably over 23%. In order to obtain thenontackiness,it has been necessary to choose the plasticizer` carefullysince most plasticizers in such high proportions will givev tackinesseven to a vinyl resin., The plasticizer-s which. we have found to besuitable in this high range are triethylene glycol di-Z-ethylbutyrateand dibutyl sebacate and mixtures of dibutyl sebacate with 4dimethoxyethyl phthalate, in which the ratio of dibutyl sebacate todimethoxyethyl phthalate is not less than 7 to 20. Even with such typesof plasticizer the upper limit of plasticizer in order to obtainnon-tackiness should not be greater than approximately 32% andpreferably should not be greater than 30%. The ideal proportion is about25 parts by weight plasticizer to 75 parts major amount compared withthe'vinyl acetate.

The invention is further illustrated in connection with the drawings. Inmaking filaments the vinyl resin composition is added to asupply chamberI, where it is heated until it has substantially no elasticity but iscapable of plastic flow. The hot molten material is then fed by a worm 2or other device through a conduit 3 and the orice 4 to the supply cup 5.A portion of the material in the supply cup 5 is grasped with a pair ofpliers or other means and drawn through the atmosphere in the form of afilament ,6. This filament is stretched as it travels over the chilledrolls 1 where the filament is farther cooled in its stretched state tosubstantially room temperature (20 C.). The cooled filament thenproceeds to the leveling reel 8 and winding reel 9 where it iscontinuously wound by means of the motor l0. The fineness of thefilament and the degree of stretch is regulated by changing the speed ofreeling, the more rapid the rate of reeling the finer the filament andthe greater the stretch. To some extent the diameter of the i'liamentmay also be regulated by changing the temperature of the moltencomposition, the hotter the composition the finer the filament. However,the upper and lower limits of temperature for the molten mass suitablefor the drawing process are determined by the decomposition temperatureof the vinyl resin composition, by the proportion of plasticizer tovinyl resin, by the type of vinyl resin, and by other factors so thatthe temperature may only be varied within narrow limits. For a conjointpolymer of vinyl chloride vinyl acetate in which the vinyl chloride isin major amount compared with the vinyl acetate, and the resin is inadmixture with 27% of a mixture of methox 20, dibutyl sebacate 7, thelower and upper temperature limits are approximately glycoldi2ethylbutyrate the lowest temperature should be about 350 F., theupper temperature about 368 F., and the ideal temperature about 358 F.

A filament speed of 24 ft. per minute will give a filament ofapproximately .05 mm. diameter for the vinyl resin compositions of thepreceding paragraph drawn from the compositions at the idealtemperatures of 347 F. and 358 F., respectively.

The molten composition may suitably be drawn without the aid of anyextrusion. The composition is pulled from a source of supply in the formof a cone of diminishing cross-section.

Filaments may be made by the process and apparatus ofghis inventionvarying from approximately 11 mm. to .01 mm. diameter. The continuousdrawing process is particularly suitable for producing elastic filamentsof .05 mm. diameter.

The following examples show compositions and procedures which have beenfound suitable, but it is not intended to limit the invention to thespecific compositions, temperatures and other The materials in the aboveformula were mixed togetherby milling. A portion of the mix was thencalendered into sheets of .04 inch thickness and cut into strips of .75inch width for test purposes. Physical tests on the strips are shown inthe following tables:

Table 1.-Stress-stram Y 'Tensile stress, lbs/111. elfggign Break TableII.-Tzmeelongatzon Time sec. Lbs/1n Jgtf'n Table III ,--Return-tzme Percent Lbs/m. emmation The remainder of the composition was then heated to347 fed through an orice of .161 inch diameter to a supply cup ofgreater crosssection than the orifice. The composition was then drawnfrom the supply cup into a lament, the filament partially cooled,stretched, further cooled to about room temperature and woundcontinuously on a reel or drum as shown in diagrammatic view of Fig. 1,the speed of reeling being such as to give a lament speed of 24 ft. perminute which gave a filament of .05 mm. diameter.

Physical tests on the drawn filament were substantially the same as forthe strips but gave somewhat higher tensile strength.

The filament produced by the continuous direct drawing, stretching andcooling process was then unwound from the reel and again stretched tosubstantially its elastic limit, immersed for fifteen minutes in waterat 212 F. and then plunged into water at 32 F. This procedure increasedthe strength of the fiber, decreased its elastic extensibility and ingeneral improved its suitability for textiles.

VIn the formula of Example I, the vinyl resin and plasticizer are shownin the preferred amounts for the carrying out of the continuous directdrawing process, and also for obtaining a filament having suitable lazystretch characteristlcs. The ratio of dibutyl sebacate to methox of 7 to20 has been found to give the best results consistent with lack of odorand suitable tensile strength. Increasing the proportion of dibutylsebacate gives an odor to the material which `may be objectionable.

temperatures of 0 F., whereas with the dibutyl sebacate the filament maybe exed at a 180 angle without cracking at such a low temperature.

The vinyl resin given in the formula of Example I was a conjoint polymerof vinyl chloride and vinyl acetate made in accordance with the ReidPatent 1,935,577, and included a small amount of basic stabilizer suchas described in Grof Patent 1,966,856. The particular vinyl resin usedwas produced by conjointly polymerizing parts by weight of vinylchloride and 20 parts of vinyl acetate, and was about 75% insoluble intoluene at 25 C. It was admixed with 1 part of calcium stearate in 100parts of resin. However, other conjoint polymers of vinyl chloride andvinyl acetate are suitable and include those ranging from vinyl chlorideand 10% vinyl acetate to 10% vinyl chloride and 90% vinyl acetate.Preferably, however, the proportion should be 80% or more of vinylchloride and 20% or less of vinyl acetate with less than 20% of theresin being soluble in cold (25 to 30 C.) toluene, and having an averagemacro molecular weight of at least 15,000` It is advisable that theresin be freed from exclusively low molecular weight polymers.

The proportion of total plasticizer (dibutyl sebacate and methox) tovinyl resin may vary -quite widely. Filaments having suitable stretchand strength characteristics for intensive direct drawing may be madewhen the proportion of plasticizer to vinyl resin is as low as 21% andas high as 32%. Preferably, however, the proportion of plasticizershould not be lower than about 22% and higher than about 30% in order toobtain satisfactory elasticity, strength, flexibility, and non-tackinessat temperatures from zero degrees Fahrenheit to F. or such as are withinthe ordinary range of atmospheric conditions. The specic preferredproportion is that shown in the formula, namely, 27 which has thephysical characteristcs heretofore indicated.

Another composition besides that shown in Example I which has been foundsuitable, is 4as follows:

EXAMPLE II Parts by weight Triethylene glycol di-2ethyl butyrate 25Counter-odorant Trace Vinyl resin 75 This composition was compounded andmade into filament in the same manner as described for the compositionof Example I. The material had slightly higher tensile strength than thematerial of Example I, and was odoriferous but not ob- Jectionably so.Otherwise its characteristics and suitability was substantially the sameas the material of Example I. The vinyl resin used was the same as inExample I. The range of suitable and.

' to limit the invention to the specific proportions and kind ofplasticizer shown.

The filaments described in this specification such as those made bydrawing the compositions of Examples l.' and II, and compositions in'which polyvinyl chloride is substituted for the vinyl resins used inExamples I and II, may be knitted, woven or otherwise fabricated intovarious articles adapted to be stretched. 'I'hese filaments giveimproved characteristics of stretch to the articles without causingdiscomfort to the wearer. These filaments have the same stress-strainand "lazy stretch characteristics as the belts, garters, suspenderstraps and the like, made from the sheets and strips. The filaments havesuch strength and elasticity that single filaments of the diameter ofordinary thread used in making hosiery can be knitted into a stockingwithout twisting or doubling the filaments into a yarn or thread.

The apparatus used in carrying out the process is shown in Figs. 1 to 6.Referring to the drawings, the apparatus comprises a supply chamber lfor holding a supply of the vinyl resin composition I2, and a stokerchamber I3 having a conduit 3 leading from the bottom of the chamber andextending upwardly to form the orice 4 and supply cup 5. The stokerchamber I3 is in the form of a trough having a grating I4 at its topthrough which the vinyl resin composition in its molten condition maypass. Below the grating is a worm or screw conveyor 2 adapted to feedthe vinyl resin composition to the orifice 4 and supply cup 5. The wormor screw conveyor 2 is driven by a -motor I through gear I5, chain driveI6 and gear I'I. The loaded supply chamber may be closed by means of aplunger I8 having a weight I9 adapted to aid the vinyl resin compositionin passing through the opening of the grate I4 so as to come in contactwith the conveyor 2.

The vinyl resin composition in the supply chamber and stoker chamber isadapted to be heated by means of a heating element in the chamber 2I. Athermostat 22 in the thermo regulator chamber 23 controls the degree ofheat.

The worm or screw conveyor 2 is adapted to continuously feed the moltenvinyl resin composition through the conduit 3 and orifice 4 to thesupply cup 5. In the preferred embodiment of the invention, the orifice4 has a diameter of .161 inch or slightly larger.

On the shaft 24 carrying the worm 2 is a gear 25 connected by a chaindrive 2B to a gear 2l e which drives a winding spool 9.

Likewise a gear 28A Is attached to the shaft 24 and by means of a chaindrive 29 and gear 30 drives the leveling reel 8. Between the levelingreel 8 and the supply cup 5 is a cooling pulley 1 which is cooled bymeans of cold water circulating through hose 3| and coupling 32.

The leveling and winding mechanism is shown in detail in Fig. 3. Thefeed device and supply source is shown in detail in Figs. 4 and 5. It isapparent from the diagrammatic view shown in Fig. 1 that the feed device2 and winding reel 9 are synchronized so that there is a constant supplyof vinyl resin composition in the supply cup 5 as the winding reelcontinuously draws a, filament from the molten composition in the supplycup.

While there have been shown and described certain embodiments of theinvention, it is to be understood that it is capable of manymodifications. Changes, therefore, may be made with.. out departing fromthe spirit and scope of the invention as described in the appendedclaims, in which it is the intention to claim all novelty inherent inthe invention as broadly as possible, in view of the prior art.

This application is a continuation in part of our` co-pendingapplication, Serial No. 318,006, filed February 8, A1940, entitledArticles of wearing apparel, accessories, and the like.

We claim:

1..'Ihe method of making a textile filament which comprises heating amixture of vinyl resin and a plasticizer to form a molten composition,feeding a. portion of said molten composition through an orifice toasupply container having a cross sectional area substantially greaterthan that of said orifice, and drawing a. filament from said molten massin said supply container Without first forming a filament while feedingmolten composition to said supply container.

2. In the method of making a textile fiber wherein a textile fiber isdirectly drawn from a vinyl resin composition without first forming afiber, the steps of drawing said hot vinyl resin composition at atemperature of above C. into a ber and cooling and pulling said fiber ina state of elastic extension through a bath of water at a temperaturebelow 75 3. The method of making a filament suitable for textiles whichcomprises heating an elastic film forming composition to a moltennon-elastic state, feeding a portion of said molten composition throughan orifice to a supply container having a cross sectional areasubstantially greater than that of said orifice, and drawing a filamentfrom the molten mass in said supply container without first forming afilament by extrusion.

4. The method of making a textile fiber which comprises directly drawinga fiber from a plastic vinyl resin composition without first forming afilament by extrusion.

HERBERT BUCHSBAUM. LEONARD BECKER.

